JP2023149943A - Cooling fluid supply structure - Google Patents

Abstract

To provide a cooling fluid supply structure which can easily establish an appropriate cooling fluid supply passage according to a shape of a grinder in coordination with attachment work of a tool unit equipped with the grinder to a main shaft.SOLUTION: A cooling fluid supply structure includes: a first supply flow passage part 101 which passes through an inside of a main shaft housing 4a and penetrates a wall surface of an engaging recessed part 30d of a tip end part of the main shaft housing; a second supply flow passage part 102 which is formed on a corotation prevention protruding part 25 of the tool unit 20 equipped with the grinder 22 by penetrating or by penetrating across the corotation prevention protruding part 25 of the tool unit 20 and a casing 24, and where an opening on one end side communicates with a downstream side opening of the first supply flow passage part 101 in an engaging state in which the corotation prevention protruding part 25 engages the engaging recessed part 30d; and a third supply flow passage part 103 which is provided outside the casing 24 of the tool unit 20, and where the opening of one end side communicates with a downstream side opening of the second supply flow passage part 102, and an opening on the other end side is located in the vicinity of a surface of the grinder 22.SELECTED DRAWING: Figure 4

Description

The present invention relates to a cooling fluid supply structure for supplying cooling fluid to the surface of a grindstone in a machine tool equipped with a spindle to which a tool unit equipped with a grindstone can be attached and detached, and a spindle housing that rotatably holds the spindle. .

BACKGROUND ART A tool unit that is detachably attached to the tip of a main spindle of a machine tool has been known (for example, see Patent Document 1). This tool unit consists of a rotary output shaft that is rotatably installed in a tapered hole provided in the main shaft, a processing tool that rotates in conjunction with the rotary output shaft, a casing that rotatably supports the rotary output shaft, and a casing that rotatably supports the rotary output shaft. and a co-rotation prevention protrusion that is fixed to and engages with an engagement recess formed on the distal end surface of the main shaft housing.

When a grindstone is used as the processing tool, a cooling fluid supply structure is required to suppress heat generation during grinding. Patent Document 2 discloses an example of a cooling fluid supply structure. This cooling fluid supply structure includes an enclosure that is attached to the casing and surrounds the grindstone, an injection nozzle that is attached to the enclosure and injects coolant into the enclosure, and a connection between the injection nozzle and a coolant supply device. Coolant piping is disclosed. The coolant supplied from the coolant supply device passes through the coolant pipe and is injected into the enclosure from the injection nozzle, and the heat generating portion of the workpiece is cooled by the injected coolant.

Japanese Patent Application Publication No. 2004-130423 Utility model registration No. 3158872

When the cooling fluid supply structure shown in Patent Document 2 is adopted, in addition to the work of mounting the tool unit in the taper hole of the spindle, it is necessary to connect the coolant piping (fluid supply path) to the injection nozzle. For this reason, there is a problem that the working time until preparations for supplying the coolant are completed becomes long.

In addition, in the cooling fluid supply structure shown in Patent Document 2, the position of the enclosure and the position of the injection nozzle are fixed regardless of the shape of the grindstone used, so the coolant (cooling fluid) is supplied to an appropriate position (for example, during processing). There is a problem in that it is not possible to accurately supply the heat to the heat-generating parts of the object. To solve this problem, a spray nozzle is fixed at the tip of the coolant pipe, and whenever the shape of the coolant pipe changes due to a change in the grindstone used, etc., the route of the coolant pipe is changed to supply coolant, which is a cooling fluid. One possibility is to adjust the position. However, in this case, there is a problem in that the time spent adjusting the coolant supply position increases, and the setup work time increases.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to easily create an appropriate cooling fluid supply path according to the shape of the grindstone in conjunction with the work of attaching a tool unit equipped with a grindstone to the main shaft. The objective is to provide a cooling fluid supply structure that can be established.

One aspect of the present invention for solving the above problem is:
The main shaft has a tool mounting hole in its distal end surface for mounting a tool unit, and a main shaft housing that rotatably holds the main shaft, and the distal end of the main shaft housing is provided with an engagement recess that is recessed toward the proximal end thereof, The tool unit includes a rotary output shaft that is fitted into the tool mounting hole, a grindstone that rotates in conjunction with the rotation of the rotary output shaft, a casing that rotatably holds the rotary output shaft, and a casing that rotatably holds the rotary output shaft. In a machine tool, the machine tool has a fixed co-rotation prevention protrusion, and the co-rotation prevention protrusion engages with the engagement recess to prevent the casing from co-rotating with the rotation of the main shaft. A cooling fluid supply structure for supplying cooling fluid to the surface of the grindstone,
a first supply flow path portion passing through the interior of the main shaft housing and penetrating the wall surface of the engagement recess and supplying cooling fluid toward the engagement recess;
One end is formed through the co-rotation prevention protrusion, or is formed so as to pass through the co-rotation prevention protrusion and the casing, and in an engaged state in which the co-rotation prevention protrusion engages with the engagement recess. a second supply flow path portion whose side opening communicates with the downstream opening of the first supply flow path portion;
The casing is provided outside the casing, and an opening at one end communicates with the downstream opening of the second supply flow path, and an opening at the other end is located near the surface of the grindstone, and is directed toward the surface of the grindstone. The present invention relates to a cooling fluid supply structure including a third supply flow path section for supplying cooling fluid.

According to this cooling fluid supply structure, when a tool unit including a grindstone as a processing tool is attached to the main shaft, a cooling fluid supply path to the surface of the grindstone is automatically established. That is, this cooling fluid supply passage consists of three parts: a first supply passage part, a second supply passage part, and a third supply passage part. The second and third supply flow path sections are provided in the tool unit. Here, the first supply flow path portion penetrates through the wall surface of the engagement recess provided at the tip of the spindle housing, and the second supply flow path portion penetrates through the co-rotation prevention protrusion of the tool unit. Alternatively, the anti-rotation protrusion and the casing are penetratingly formed. Therefore, when the co-rotation prevention protrusion is engaged with the engagement recess of the spindle housing when the tool unit is attached to the spindle, the opening on the downstream side of the first supply passage and the opening on the one end side of the second supply passage communicate with. Since the second supply flow path section and the third supply flow path section are originally in communication regardless of whether or not the co-rotation prevention protrusion is engaged, as a result, the first to third supply flow path sections are connected at once. , a cooling fluid supply path to the grinding wheel surface is formed.

Therefore, the cooling fluid supply path can be easily installed and removed in conjunction with the work of attaching and detaching the tool unit to and from the main shaft, and the setup work time can be shortened. In addition, by setting the wiring path of the third supply flow path section that discharges cooling fluid toward the grinding wheel appropriately in advance according to the shape of the grinding wheel, the shape of the grinding wheel can be changed by replacing the tool unit, etc. Even in this case, it is possible to establish an appropriate cooling fluid supply path according to the shape of the grindstone. Note that an appropriate cooling fluid supply path according to the shape of the grinding wheel is defined as, for example, a flow path that can supply cooling fluid to the heat generating part of the workpiece (the contact point with the grinding wheel in the workpiece). This definition is not limited to, and may be changed as appropriate depending on the usage status of the grindstone.

Moreover, since the first supply flow path section is formed inside the spindle housing, there is no need to separately secure piping space for the cooling fluid, and space efficiency can be improved. Furthermore, the first supply passage on the spindle side and the second supply passage on the tool unit side are brought into communication by the engagement of the co-rotation prevention protrusion provided on the tool unit and the engagement recess on the spindle housing. Because of this, the co-rotation prevention protrusion also serves as a connector for connecting the flow path. Therefore, there is no need to separately provide a connector for connecting the flow path to the tool unit, and there is no need to separately provide an adapter for connection on the front end surface of the spindle housing. Therefore, the number of parts can be reduced and manufacturing costs can be reduced.

The engagement recess is formed in a mounting member separate from the main shaft housing that is attached to the front end surface of the main shaft housing, and the first supply passage portion is formed in the main shaft interior formed in the main shaft housing. It is preferable that the main shaft external flow path is formed to penetrate through the mounting member.

According to this configuration, by forming the engagement recess with which the co-rotation prevention protrusion engages in a mounting member separate from the spindle housing, for example, when the tool unit is replaced, the co-rotation prevention protrusion can be removed. Even if the position changes, this can be dealt with simply by replacing the mounting member with another mounting member with a different position of the engagement recess. Furthermore, by changing the shape of the spindle external flow path formed in the mounting member, the position of the downstream opening of the first supply flow path portion can be easily changed. Therefore, even if the position of the second supply flow path formed on the co-rotation prevention protrusion changes due to replacement of the tool unit, the first supply flow path and the second supply flow path can be changed by simply replacing the mounting member. The parts can be easily communicated with each other.

It is preferable that the mounting member is removably fixed to the tip surface of the spindle housing via a screw that is threaded into a screw hole formed in the tip surface of the spindle housing.

According to this configuration, it is possible to easily replace the mounting member.

It is preferable that the first supply channel section is a linear channel extending in the axial direction of the main shaft.

According to this configuration, by forming the first supply flow path section in a linear shape, it is possible to reduce the pipe resistance acting on the cooling fluid in the first supply flow path section. Thereby, the cooling fluid can be vigorously supplied from the first supply flow path section to the second supply flow path section connected to the downstream side thereof.

It is preferable that the second supply flow path section is a linear flow path extending in the axial direction of the main shaft in the engaged state.

According to this configuration, by forming the second supply flow path section in a linear shape, it is possible to reduce the pipe resistance acting on the cooling fluid in the second supply flow path section. Thereby, the cooling fluid can be vigorously supplied from the second supply flow path section to the third supply flow path section connected to the downstream side thereof.

It is preferable that, in the engaged state, the first supply flow path section and the second supply flow path section extend linearly in the axial direction of the main shaft and are arranged coaxially with each other.

According to this configuration, since the first supply flow path section and the second supply flow path section are arranged coaxially, when the cooling fluid flows from the first supply flow path section to the second supply flow path section, can reduce pipe resistance. In addition, since the first supply flow path section and the second supply flow path section cooperate to form one straight fluid supply path extending in the axial direction of the main shaft, even if the fluid supply path is bent, In comparison, the pipe resistance acting on the cooling fluid can be significantly reduced.

It is preferable that the third supply flow path section is formed by flexible piping.

According to this configuration, by changing the curved shape of the flexible pipe, the location where the cooling fluid is supplied to the grindstone can be freely adjusted. Therefore, the cooling fluid can be accurately supplied toward, for example, the heat-generating portion of the workpiece.

According to the present invention, the first supply passage passes through the inside of the spindle housing and penetrates the wall surface of the engagement recess at the tip thereof, and the first supply flow passage passes through the co-rotation prevention protrusion of the tool unit equipped with a grindstone as a processing tool. or is formed so as to penetrate across the co-rotation prevention protrusion and the casing of the tool unit, and in the engaged state in which the co-rotation prevention protrusion engages with the engagement recess, the opening on one end side is connected to the first a second supply flow path section that communicates with the downstream opening of the supply flow path section; and a second supply flow path section provided outside the casing of the tool unit, with an opening at one end communicating with the downstream opening of the second supply flow path section; Since the opening on the other end side is provided with a third supply flow path portion located near the surface of the grinding wheel, the tool unit can be attached to the main spindle of the tool unit, and can be properly adjusted according to the shape of the grinding wheel. A cooling fluid supply path can be easily established. Therefore, the setup work time associated with tool unit replacement can be shortened as much as possible.

1 is a schematic side view showing a machine tool equipped with a coolant supply structure (an example of a cooling fluid supply structure) according to an embodiment of the present invention. FIG. 3 is a partial cross-sectional view of the spindle head taken horizontally along its axis. FIG. 2 is an external perspective view showing a tool unit equipped with a grindstone. FIG. 2 is a partial cross-sectional view of the spindle head with the tool unit mounted thereon, taken horizontally along its axis. FIG. 5 is an enlarged view showing the V section of FIG. 4 in an enlarged manner. (a) is a side view of the attachment member, and (b) is a front view of the attachment member viewed from the engagement recess side. It is an explanatory view for explaining a mounting member concerning other embodiments. It is an explanatory view for explaining the composition of the 2nd supply channel part concerning other embodiments.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

《Embodiment》
FIG. 1 is a right side view showing a machine tool 1 equipped with a coolant supply structure (an example of a cooling fluid supply structure) according to an embodiment. This machine tool 1 is a horizontal machining center, and includes a bed 2, a column 3, a spindle head 4, a spindle 5, a table 6, and the like. The entire machine tool 1 is covered by a splash guard 7 that forms its exterior. Note that in FIG. 1 showing the entire machine tool 1, only the main parts that are the main components of the machine tool 1 are shown.

The bed 2 as a whole is formed into a substantially T-shape in plan view, and the table 6 is disposed on the bed 2 and is guided by a guide rail (not shown) in the front-rear direction of the bed 2, that is, in the horizontal direction. It is provided to move in the indicated Z-axis direction. A work W to be processed (shown only in FIG. 1) is set on the table 6 via a pallet P.

The column 3 is disposed on the bed 2 and is guided by a guide rail 8 so as to move in an X-axis direction (perpendicular to the plane of the paper in FIG. 1) that is horizontally orthogonal to the Z-axis. A spindle head 4 is supported on the column 3. The spindle head 4 has a spindle housing 4a (see FIG. 2). A main shaft 5 is rotatably held in the main shaft housing 4a via a bearing 11. A processing tool K is removably attached to the main shaft 5 via a tool holder or as part of a tool unit 20 (see FIG. 3), which will be described later. In the following, unless otherwise specified, a case will be described in which the processing tool K is mounted on the spindle 5 as a part of the tool unit 20, as in the latter case.

The spindle head 4 is held by the column 3 so as to be movable in the vertical Y-axis direction perpendicular to the X-axis and the Z-axis. In this way, the spindle head 4 moves within the X-axis-Y-axis plane.

The column 3 is fed and driven in the X-axis direction by an X-axis feed mechanism (not shown), the spindle head 4 is fed and driven in the Y-axis direction by a Y-axis feed mechanism (not shown), and the table 6 is fed and driven in the Y-axis direction by a Y-axis feed mechanism (not shown). It is fed and driven in the Z-axis direction by a feeding mechanism (not shown). These X-axis feeding mechanism, Y-axis feeding mechanism, and Z-axis feeding mechanism are configured by, for example, a combination of a ball screw and a motor. Each feed mechanism, the main shaft 5, and a main shaft motor (not shown) that drives the main shaft 5 function as a processing mechanism section 9.

The processing mechanism section 9 controls the workpiece W by changing the relative position between the processing tool K attached to the spindle 5 and the workpiece W set on the table 6 under the control of the control device 50 (see FIG. 2). Process into the desired shape. The control device 50 is a computer having a CPU, ROM, and RAM, and controls the operation of the processing mechanism section 9 based on an NC program stored in a hard disk or the like.

The machine tool 1 further includes a coolant supply device 10 (see FIG. 2) that supplies coolant liquid into the machining area for purposes such as cooling and lubricating the machining area and discharging chips.

The coolant supply device 10 sucks coolant liquid stored in a storage tank using a supply pump (not shown), and supplies the sucked coolant liquid to a processing portion of the workpiece W. The supplied coolant liquid is collected into the storage tank via a return pipe connected to the lower part of the bed 2. The operation of the coolant supply device 10 is controlled by the control device 50.

[Details of main shaft structure]
As shown in FIG. 2, the main shaft housing 4a includes a substantially cylindrical housing main body 4b and a distal end cover portion 4c that covers the distal end side of the housing main body 4b. The tip cover portion 4c has a spigot portion and is attached to the tip portion of the housing body portion 4b from the outside in the axial direction.

A through hole 4e is formed in the main shaft housing 4a. The through hole 4e is located radially outward of the bearing 11 in the main shaft housing 4a, and extends parallel to the axis of the main shaft 5 across the housing main body portion 4b and the tip cover portion 4c. One end of the through hole 4e is connected to the coolant supply device 10 via a solenoid valve 51, and the other end is open to the front end surface of the main shaft housing 4a. The solenoid valve 51 is driven to open and close by the control device 50. When the electromagnetic valve 51 is excited and driven in the opening direction, coolant liquid is supplied from the coolant supply device 10 into the through hole 4e. An O-ring groove 4f is formed in the contact surface of the housing body 4b with the tip cover 4c so as to surround the through hole 4e, and an O-ring 35 is fitted into the O-ring groove 4f.

The main shaft 5 is disposed radially inside the housing main body portion 4b and the tip cover portion 4c. The main shaft 5 is rotatably supported by a bearing 11 fitted to the inner circumferential surface of the housing main body 4b. Two bearings 11 are arranged at each of the distal end side and the proximal end side of the housing main body portion 4b. In FIG. 2, the drawing is simplified and only two bearings 11 on the tip side are shown. The number and arrangement of the bearings 11 are not limited to this. Further, the type of bearing 11 is not limited to a rolling bearing, and may be a sliding bearing, for example.

The main shaft 5 has a tool mounting hole 5a into which a tool unit 20 (see FIG. 3) is mounted, and a through hole 5b in which a collet 12 for holding the tool unit 20 on the main shaft 5 is accommodated.

The tool mounting hole 5a opens at the distal end surface of the main spindle 5, and tapers in diameter from the distal end side to the proximal end side of the main spindle 5. When mounting the tool unit 20 on the spindle 5, the shank 21a of the tool unit 20 is fitted into the tool mounting hole 5a. In this example, the attachment/detachment of the tool unit 20 to/from the tool mounting hole 5a is automatically performed by an ATC (Automatic tool changer) device installed in the machine tool 1, but is not limited to this. may be performed manually.

The through hole 5b extends coaxially with the main shaft 5 in its axial direction, and communicates with the base end of the tool mounting hole 5a. The collet 12 is housed in the through hole 5b so as to be movable in the axial direction of the main shaft 5. The collet 12 is connected to a drawbar mechanism (not shown). When the collet 12 is moved to the base end side of the main shaft 5 by this drawbar mechanism, the collet 12 is closed, and the pull stud 21g of the tool unit 20 is gripped by the collet 12, and the pull stud 21g is moved toward the base end side of the main shaft 5. be drawn into. Thereby, the shank 21a of the tool unit 20 is firmly fitted into the tool mounting hole 5a, and the tool unit 20 is fixed to the main shaft 5. When removing the tool unit 20 from the main spindle 5, the collet 12 is moved to the tip side of the main spindle 5 by the drawbar mechanism. As a result, the collet 12 is opened, the grip of the shank 21a by the collet 12 is released, and the tool unit 20 can be pulled out from the tool mounting hole 5a.

FIG. 3 is a perspective view showing an example of the tool unit 20 attached to the spindle 5, and FIG. 4 is a longitudinal sectional view showing the tool unit 20 attached to the spindle 5. In FIGS. 3 and 4, the workpiece W is omitted from the drawings. In addition, in the following description, the tip side and base end side of the tool unit 20 in the axial direction are defined as the front side of the unit and the rear side of the unit, respectively.

This tool unit 20 includes a grindstone 22 as a processing tool K. Although FIGS. 3 and 4 show an example in which the grindstone 22 is disc-shaped, the shape of the grindstone 22 is not limited to this, and may be, for example, conical. When the tool unit 20 is attached to the main shaft 5, a cooling flow path (see the white arrow in FIG. 4) for supplying coolant liquid to the grindstone 22 is formed. This cooling channel is composed of a first supply channel section 101, a second supply channel section 102, and a third supply channel section 103. Details of each supply flow path section 101 to 103 will be described later.

The tool unit 20 includes a rotary output shaft 21, the grindstone 22 fixed to the tip of the rotary output shaft 21, a pair of bearings 23 that rotatably supports the rotary output shaft 21, and a pair of bearings 23 installed inside the rotary output shaft 21. It has a casing 24 housed in the casing 24, and a co-rotation prevention pin 25 connected to the casing 24.

The pair of bearings 23 are arranged at intervals in the axial direction of the rotation output shaft 21 . A spacer 26 is arranged between the pair of bearings 23 to regulate the distance between them. The number and arrangement of the bearings 23 are not limited to this. Further, the type of bearing 23 is not limited to a rolling bearing, and may be a sliding bearing, for example.

The rotation output shaft 21 has a tapered shank 21a that can be fitted into the tool mounting hole 5a of the main shaft 5, and is connected to the tip of the shank 21a with a flange portion 21b interposed therebetween, and a pair of bearings 23 are fitted onto the outside. A shaft main body part 21c, a nut engaging shaft part 21d into which a nut 27 for fixing the pair of bearings 23 is screwed, and a grinding wheel 22 connected to the shaft tip side of the nut engaging shaft part 21d. The tool mounting shaft 21e has a tapered tool mounting shaft portion 21e, and a tip threaded portion 21f connected to the tip of the tool mounting shaft portion 21e. A nut 28 for fixing the grindstone 22 is screwed into the tip threaded portion 21f.

A pull stud 21g, which is detachably held by the collet 12, is connected to the base end of the shank 21a. Although various standards are available for the shape of the shank 21a, the BBT standard is adopted in the example shown in FIG. Note that the standard of the shank 21a is not limited to the BBT standard, and other standards such as the BT standard or the HSK standard may be adopted, for example.

The flange portion 21b has a groove portion 21h having a substantially V-shaped cross section and extending over the entire circumference of the outer peripheral surface. The groove portion 21h is used when the tool unit 20 is automatically replaced by the ATC device. Specifically, when the tool unit 20 is automatically replaced, the claw portion of the ATC arm engages with the groove portion 21h, so that the tool unit 20 is held by the ATC arm.

The casing 24 includes a cylindrical bearing accommodating tube portion 24a that accommodates the pair of bearings 23, a tip cover portion 24b attached to one end of the bearing accommodating tube portion 24a in the axial direction, and a cylindrical bearing accommodating tube portion 24a that is attached to the bearing accommodating tube portion 24a. a pin holding part 24c which is arranged apart from each other radially outward and holds the co-rotation prevention pin 25; and a connecting part 24d which connects the pin holding part 24c and the bearing housing cylinder part 24a to each other. There is.

The pin holding portion 24c has a substantially cylindrical shape in appearance. As shown in FIG. 5, the pin holding portion 24c has a guide hole 24e that slidably guides the co-rotation prevention pin 25. The axis of the guide hole 24e extends parallel to the axis of the rotation output shaft 21, and the distance between these two axes is equal to the axis of the main shaft 5 and the through hole 4e formed in the main shaft housing 4a (see FIG. 4). Equal to the distance from the axis. The guide hole 24e is a blind hole that opens toward the rear of the unit. The co-rotation prevention pin 25 is fitted into the guide hole 24e so that a portion of the tip side protrudes toward the rear side of the unit. The co-rotation prevention pin 25 is guided by the guide hole 24e so as to be freely advanced and retracted in the axial direction thereof. The edge of the tip of the co-rotation prevention pin 25 is chamfered at approximately 45 degrees.

Inside the co-rotation prevention pin 25, a small diameter hole 25a and a large diameter hole 25c connected to the small diameter hole 25a via a stepped surface 25b are formed penetratingly in the pin axial direction. The small diameter hole 25a opens at the distal end surface 25g (end surface on the protruding side) of the co-rotation prevention pin 25, and the large diameter hole 25c opens at the proximal end surface 25f of the co-rotation prevention pin 25. A compression coil spring 34 is disposed in a compressed state between the stepped surface 25b and the inner end surface 24i of the guide hole 24e. The co-rotation prevention pin 25 is urged toward the rear of the unit by this compression coil spring 34.

As shown in FIG. 5, the space inside the co-rotation prevention pin 25 and the space in the guide hole 24e on the bottom side of the base end surface 25f of the co-rotation prevention pin 25 is used for cooling during grinding as described later. filled with coolant fluid. The surface dimensions of the co-rotation prevention pin 25 are set so that the co-rotation prevention pin 25 advances toward the rear side of the unit due to the pressure of this coolant liquid. That is, when the area of the step surface 25b of the co-rotation prevention pin 25 is A1, the area of the proximal end surface 25f is A2, and the area of the distal end surface 25g is A3, the relationship A1+A2>A3 is satisfied. According to this, the thrust force toward the rear of the unit caused by coolant pressure acting on the step surface 25b and the base end surface 25f of the co-rotation pin is caused by the coolant pressure acting on the tip surface 25g of the co-rotation prevention pin 25. This exceeds the thrust force generated toward the front of the unit. Therefore, the co-rotation prevention pin 25 can be firmly brought into close contact with the engagement recess 30d of the mounting member 30 located on the rear side of the unit, and leakage of coolant can be prevented.

An O-ring groove 25d is formed in a surface portion of the outer peripheral surface of the co-rotation prevention pin 25 that fits into the guide hole 24e. An O-ring 33 is fitted into the O-ring groove 25d.

A through hole 24f is formed in the guide end wall 24j of the pin holding portion 24c that forms the inner end surface 24i of the guide hole 24e. The through hole 24f is formed coaxially with the small diameter hole 25a and the large diameter hole 25c of the co-rotation prevention pin 25. The through hole 24f has a pore portion 24m that opens at the inner end surface 24i of the guide hole 24e, and a female screw portion for connecting a pipe located on the inner peripheral surface of the pore portion 24m on the front side of the unit. It consists of a screw hole portion 24n. One end of a flexible pipe 36, which will be described later, is screwed into the screw hole 24n.

A protruding plate 25e is formed on the outer circumferential surface of the co-rotation prevention pin 25. The protruding plate 25e protrudes toward the rotation center of the tool unit 20 (toward the bearing accommodating cylindrical portion 24a). The co-rotation prevention pin 25 is guided in a direction parallel to the axis of the guide hole 24e by a retaining pin 29 passing through the protruding plate 25e. The retaining pin 29 is fixed by screwing a threaded portion at its tip into a threaded hole 24k formed on the rear side of the unit of the connecting portion 24d. When the head of this retaining pin 29 comes into contact with the protruding plate 25e, the amount of movement of the co-rotation prevention pin 25 toward the rear of the unit is restricted, and the co-rotation prevention pin 25 is prevented from slipping out from the guide hole 24e. ing.

The co-rotation prevention pin 25 engages with the engagement recess 30d of the mounting member 30 fixed to the spindle housing 4a when the tool unit 20 is attached to the spindle 5. Through this engagement, the casing 24 of the tool unit 20 is connected to the main shaft housing 4a, which is a stationary member, via the co-rotation prevention pin 25 and the attachment member 30. This prevents the casing 24 from rotating together when the main shaft 5 rotates. In this way, the co-rotation prevention pin 25 functions as a co-rotation prevention protrusion.

As shown in FIG. 3, the tip of the protruding plate 25e connected to the outer peripheral surface of the co-rotation prevention pin 25 is attached to the flange portion 21b of the rotation output shaft 21 when the tool unit 20 is not attached to the main shaft 5. It engages with the formed engagement groove 21i. This engagement groove 21i is located on the outer circumferential portion of the flange portion 21b, and is open to the radially outer side of the flange portion 21b and to the front side of the unit. Then, the tip of the protruding plate 25e engages with the engagement groove 21i of the rotation output shaft 21, whereby the casing 24 is prevented from rotating relative to the rotation output shaft 21. Therefore, for example, when the tool unit 20 is housed in a tool magazine of an ATC device, it is possible to prevent the casing 24 from rotating unnecessarily with respect to the rotation output shaft 21.

On the other hand, when the tool unit 20 is attached to the main shaft 5 as shown in FIG. In response to the reaction force, the unit moves slightly toward the front side (to the right in FIG. 4) while resisting the biasing force of the compression coil spring 34. As a result, the tip of the protruding plate 25e connected to the co-rotation prevention pin 25 moves to the outside of the engagement groove 21i of the rotary output shaft 21, and the above-described anti-rotation function of the protruding plate 25e is released. Thereby, the rotation output shaft 21 becomes rotatable independently of the casing 24 while being supported by the casing 24 .

[Configuration of mounting parts]
As shown in FIGS. 5 and 6, the mounting member 30 includes a bracket portion 30a forming a mounting seat surface, and a cylindrical boss portion 30b protruding from the side opposite to the mounting seat surface of the bracket portion 30a. are doing.

The mounting member 30 has an engagement recess 30d that opens at the end surface of the cylindrical boss portion 30b, and a communication hole 30g that is connected to the engagement recess 30d and opens to the mounting seat surface. The communication hole 30g is formed so that the through hole 4e of the spindle housing 4a and the engagement recess 30d communicate with each other when the mounting member 30 is attached to the distal end surface of the spindle housing 4a.

The engagement recess 30d includes a cylindrical hole 30e that is coaxial with the cylindrical boss 30b, and a tapered hole 30f that is connected to the cylindrical hole 30e and whose diameter decreases toward the mounting seat surface. The cylindrical hole portion 30e is formed to fit into the outer peripheral surface of the co-rotation prevention pin 25. The tapered hole portion 30f is formed to fit into a chamfered portion on the tip side of the co-rotation prevention pin 25.

An O-ring groove 30h is formed in the mounting seat surface of the mounting member 30 so as to surround the communication hole 30g. An O-ring 32 is fitted into this O-ring groove 30h.

A pair of attachment holes 30c are formed in the bracket portion 30a, passing through the bracket portion 30a in the thickness direction. The pair of attachment holes 30c are arranged symmetrically across the cylindrical boss portion 30b when viewed from the bracket thickness direction. The mounting member 30 is fixed to the front end surface of the main shaft housing 4a by bolts 31 passing through each mounting hole 30c. A screw hole 4d into which the bolt 31 is screwed is formed in the tip end surface of the main shaft housing 4a. As the screw hole 4d, an existing screw hole formed in the front end surface of the main shaft housing 4a can be used. When the mounting member 30 is fixed to the distal end surface of the spindle housing 4a, the through hole 4e formed in the spindle housing 4a communicates with the engagement recess 30d via the communication hole 30g of the mounting member 30.

[Coolant supply structure]
Next, a coolant supply structure for supplying coolant liquid, which is a cooling fluid, to the surface of the grindstone 22 will be described. Note that the white arrows shown in each figure schematically indicate the flow of the coolant liquid.

As shown in FIG. 4, this coolant supply structure includes a first supply flow path section 101, a second supply flow path section 102, and a third supply flow path section 103.

As shown in FIG. 4, the first supply flow path section 101 includes a through hole 4e formed in the spindle housing 4a and a communication hole 30g formed in the mounting member 30. The through hole 4e corresponds to the main shaft internal flow path, and the communication hole 30g corresponds to the main shaft external flow path.

As shown in FIGS. 4 and 5, the second supply flow path section 102 passes through the co-rotation prevention pin 25 of the tool unit 20 and the guide end wall 24j of the casing 24. Specifically, the second supply flow path section 102 includes a small diameter hole 25a and a large diameter hole 25c formed inside the co-rotation prevention pin 25, and a through hole 24f formed in the guide end wall 24j. ing. The small diameter hole 25a, the large diameter hole 25c, and the through hole 24f are arranged coaxially and linearly with each other along the axial direction of the main shaft 5. That is, the second supply channel section 102 is a linear channel extending parallel to the axial direction of the main shaft 5. The opening at one end of the second supply channel section 102 communicates with the downstream opening of the first supply channel section 101 (ie, the downstream opening of the communication hole 30g). The opening on the other end side of the second supply flow path section 102 communicates with a third supply flow path section 103, which will be described later.

As shown in FIG. 4, the third supply flow path section 103 includes a flow path in the flexible pipe 36 connected to the through hole 24f and a flow path in the diverging nozzle 37 connected to the tip of the flexible pipe 36. It is configured. The flexible piping 36 extends from the through hole 24f toward the front of the unit, bends radially outward along the side surface of the grindstone 22, and then bends toward the front of the unit to a position close to the outer peripheral surface of the grindstone 22. It is extending. A diverging nozzle 37 is connected to the end of the flexible pipe 36 on the grindstone 22 side. The wide-divergent nozzle 37 is a flat nozzle whose flow path width becomes wider toward the downstream side, and is arranged so that its discharge opening is located near the surface of the grindstone 22 . Specifically, the diverging nozzle 37 is arranged such that its discharge port faces the outer circumferential surface of the grindstone with a predetermined distance therebetween. Here, the predetermined interval is set within a range in which the coolant liquid can be supplied toward the heat generating location of the workpiece W (the contact location with the grindstone 22 on the workpiece W). In this example, the discharge port of the wide-spread nozzle 37 faces the outer circumferential surface of the grindstone 22, but is not limited to this, and may also face the side surface of the grindstone 22, or They may be offset instead of facing each other.

In the machine tool 1 configured as described above, when the tool unit 20 is not mounted on the spindle 5, the first supply flow path section 101 opens near the tip of the spindle 5, as shown in FIG. It does not function as a coolant supply path. On the other hand, as shown in FIG. 4, when the tool unit 20 is attached to the main shaft 5, the co-rotation prevention pin 25 engages with the engagement recess 30d of the mounting member 30. When the co-rotation prevention pin 25 engages with the engagement recess 30d, the downstream opening of the first supply flow path section 101 (the downstream opening of the communication hole 30g of the mounting member 30) and the upstream side of the second supply flow path section 102 The side opening (the opening on the upstream side of the small diameter hole 25a of the co-rotation prevention pin 25) communicates. Since the second supply flow path section 102 and the third supply flow path section 103 are originally provided in the tool unit 20 and communicate with each other, the three supply flow path sections 101 to 103 are connected at once, and the coolant supply device A coolant liquid supply channel (the channel indicated by the white arrow in FIG. 4) is formed from 10 to near the surface of the grindstone 22.

During the grinding process using the grindstone 22, the solenoid valve 51 is excited and driven in the opening direction under the control of the control device 50, and the coolant liquid discharged from the coolant supply device 10 flows into the first supply flow path section 101. Thereafter, it is supplied to the heat generating portion of the workpiece W (the contact portion of the workpiece W with the grindstone 22) via the second supply flow path section 102 and the third supply flow path section 103 provided in the tool unit 20.

In addition, in a machining operation in which a normal tool holder that does not have the co-rotation prevention pin 25 is attached to the spindle 5, the control device 50 recognizes this based on the analysis content of the NC program and moves the solenoid valve 51 in the closing direction. Excitation drive. Therefore, during normal machining operations that do not require the co-rotation prevention pin 25, the coolant liquid is not unnecessarily sprayed from the tip of the first supply flow path section 101.

[Operations and effects of this embodiment]
As explained above, according to the coolant supply structure of the present embodiment, the first supply passage section 101 passes through the interior of the spindle housing 4a and the wall surface of the engagement recess 30d at the tip thereof, and the tool unit 20 In the engaged state in which the co-rotation prevention pin 25 and the casing 24 are interlocked, the opening on one end side is formed to penetrate the co-rotation prevention pin 25 and the casing 24. A second supply flow path section 102 that communicates with the downstream opening, and an opening provided on the outside of the casing 24 of the tool unit 20, with an opening at one end communicating with the downstream opening of the second supply flow path section 102 and the other. Since the opening on the end side is provided with the third supply passage section 103 located near the surface of the grinding wheel 22, coolant can be supplied to the grinding wheel 22 in conjunction with the attachment/detachment work of the tool unit 20 to the main shaft 5. Roads can be easily installed and removed. Therefore, the setup work time required for replacing the tool unit 20 can be shortened as much as possible. In addition, by appropriately setting the wiring path of the third supply flow path section 103 that discharges coolant toward the grindstone 22 according to the shape of the grindstone 22, it is possible to remove the coolant from the grindstone by replacing the tool unit 20, etc. Even if the shape of the grindstone 22 is changed, an appropriate coolant supply path can be established according to the shape of the grindstone 22.

Moreover, since most of the first supply flow path section 101 is formed inside the main shaft housing 4a, there is no need to separately secure piping space for the coolant liquid, and space efficiency can be improved. Also, due to the engagement between the co-rotation prevention pin 25 provided on the tool unit 20 and the engagement recess 30d, the first supply flow path section 101 on the main spindle 5 side and the second supply flow path section 102 on the tool unit 20 side are connected. The co-rotation prevention pin 25 also serves as a connector for connecting the flow path. Therefore, it is possible to standardize parts and reduce costs.

Further, the engagement recess 30d is formed in a mounting member 30 that is separate from the main shaft housing 4a and is attached to the front end surface of the main shaft housing 4a, and the first supply flow path section 101 is formed on the main shaft housing 4a. It consists of a through hole 4e as a main shaft internal flow path and a communication hole 30g as a main shaft external flow path formed through the mounting member 30.

According to this, by forming the engagement recess 30d with which the co-rotation prevention pin 25 engages in the mounting member 30 separate from the spindle housing 4a, co-rotation can be prevented by, for example, replacing the tool unit 20. Even if the position of the pin 25 changes, this can be handled by simply changing the shapes of the engagement recess 30d and the communication hole 30g formed in the mounting member 30 (see FIG. 7, which will be described later).

The mounting member 30 is removably fixed to the front end surface of the spindle housing 4a by a bolt 31 that is threaded into a screw hole 4d formed at the front end surface of the main shaft housing 4a.

According to this, the work of replacing the mounting member 30 can be easily performed. As this screw hole 4d, an existing screw hole formed in the front end surface of the main shaft housing 4a can be used.

The first supply channel portion 101 is a linear channel extending in the axial direction of the main shaft 5 .

According to this configuration, by forming the first supply flow path section 101 in a linear shape, the pipe resistance within the first supply flow path section 101 can be reduced. Thereby, the coolant liquid can be vigorously supplied from the first supply flow path section 101 toward the second supply flow path section 102 connected to the downstream side thereof.

The second supply flow path section 102 is formed to extend linearly in the axial direction of the main shaft 5 when the co-rotation prevention pin 25 is engaged with the engagement recess 30d of the mounting member 30.

According to this configuration, by forming the second supply flow path section 102 in a linear shape, the pipe resistance within the second supply flow path section 102 can be reduced. Thereby, the coolant liquid can be vigorously supplied from the second supply flow path section 102 toward the third supply flow path section 103 connected to the downstream side thereof.

The first supply flow path section 101 and the second supply flow path section 102 extend linearly in the axial direction of the main shaft 5 when the co-rotation prevention pin 25 is engaged with the engagement recess 30d of the mounting member 30. are arranged coaxially with each other.

According to this, since the first supply flow path section 101 and the second supply flow path section 102 are arranged coaxially, the coolant liquid flows from the first supply flow path section 101 to the second supply flow path section 102. It is possible to reduce the conduit resistance when In addition, since the first supply flow path section 101 and the second supply flow path section 102 cooperate to form one linear fluid supply path, the pipe resistance acting on the coolant liquid is reduced as much as possible. can do.

Further, the third supply flow path section 103 is formed by flexible piping 36.

According to this, by changing the curved shape of the flexible pipe 36, the location where the coolant liquid is supplied to the grindstone 22 can be freely adjusted. Therefore, the coolant liquid can be accurately supplied to the heat-generating portions of the workpiece W, and the cooling efficiency thereof can be improved.

《Other embodiments》
In the embodiment described above, the tool unit 20 is configured such that the axis of the main spindle 5 and the axis of the grindstone 22 face in the same direction; however, the axis line of the main spindle 5 and the axis of the grindstone 22 are not limited to this. may be configured to intersect at a predetermined angle (for example, 90°). In this case, a gear mechanism for intersecting the rotation axes may be added inside the casing 24.

In the embodiment described above, the cooling fluid for cooling the grindstone 22 is a coolant liquid, but the cooling fluid is not limited to this. The cooling fluid may be, for example, cooling air or an inert gas.

In the embodiment described above, an example has been described in which the through hole 4e formed in the spindle housing 4a and the co-rotation prevention pin 25 of the tool unit 20 are located coaxially, but for example, as shown in FIG. The axis of the pin 25 may be offset to the outside in the radial direction of the main shaft housing 4a (lower side in FIG. 7) with respect to the axis of the through hole 4e. In this case, by shifting the position of the communication hole 30g formed in the mounting member 30 in a direction that absorbs this offset, that is, inward in the radial direction of the spindle housing 4a (upper side in FIG. 6), the communication hole 30g can rotate together with the through hole 4e. The small diameter hole 25a in the prevention pin 25 communicates with the small diameter hole 25a through the communication hole 30g. Therefore, the same effects as those of the embodiment described above can be obtained.

In the embodiment described above, the second supply flow path section 102 is formed to extend across the co-rotation prevention pin 25 and the guide end wall 24j of the casing 24, but is not limited to this, and for example, As shown in FIG. 8, only the co-rotation prevention pin 25 may be penetrated. In the example of FIG. 8, the co-rotation prevention pin 25 is fixed to the casing 24, the flexible piping 36 is connected to the co-rotation prevention pin 25 from the radial outside (side), and the small diameter hole in the co-rotation prevention pin 25 is 25a and a flow path within the flexible piping 36 are in communication.

In the embodiment, the first supply channel section 101 can also be used for a tool unit that includes a cutting tool such as a drill as the processing tool K. In this case, the coolant liquid supplied to the first supply flow path section 101 passes through a flow path in the casing and a flow path formed inside the rotary output shaft by a well-known method such as a center-through method or a side-through method. It is supplied to the tip of the processing tool K. In this way, the coolant supply structure can be simplified by using the first supply passage section 101 for both the tool unit adopting the center-through method or the side-through method and the tool unit 20 of the above embodiment equipped with the grindstone 22. can be used to reduce costs.

In the embodiment, the co-rotation prevention pin 25 is configured as a separate member from the casing 24, but is not limited to this, and may be integrally formed with the casing 24.

In the embodiment described above, the engagement recess 30d is formed in the mounting member 30 separate from the spindle housing 4a, but the engagement recess 30d is not limited to this. Good too.

In the embodiment described above, the flexible piping 36 is used to form the third supply flow path section 103, but it is not necessary to use the flexible piping 36, and instead it is preferable to use a fixed piping with a fixed shape. It's okay. Moreover, the wide-divergent nozzle 37 may be abolished.

In the embodiment, the machine tool 1 is a horizontal machining center, but it is not limited to this, and may be, for example, a vertical machining center or a multi-tasking machine.

Note that the description of the embodiments described above is illustrative in all respects and is not restrictive. Modifications and changes can be made as appropriate by those skilled in the art. The scope of the invention is indicated by the claims rather than the embodiments described above. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of the claims and equivalents.

1 Machine tool 4a Main shaft housing 4d Screw hole 5 Main shaft 5a Tool mounting hole 20 Tool unit 21 Rotary output shaft 22 Grindstone 24 Casing 25 Co-rotation prevention pin (co-rotation prevention protrusion)
30 Mounting member 30d Engagement recess 36 Flexible piping 101 First supply flow path section 102 Second supply flow path section 103 Third supply flow path section

Claims (7)

The main shaft has a tool mounting hole in its distal end surface for mounting a tool unit, and a main shaft housing that rotatably holds the main shaft, and the distal end of the main shaft housing is provided with an engagement recess that is recessed toward the proximal end thereof, The tool unit includes a rotary output shaft that is fitted into the tool mounting hole, a grindstone that rotates in conjunction with the rotation of the rotary output shaft, a casing that rotatably holds the rotary output shaft, and a casing that rotatably holds the rotary output shaft. In a machine tool, the machine tool has a fixed co-rotation prevention protrusion, and the co-rotation prevention protrusion engages with the engagement recess to prevent the casing from co-rotating with the rotation of the main shaft. A cooling fluid supply structure for supplying cooling fluid to the surface of the grindstone,
a first supply flow path portion passing through the interior of the main shaft housing and penetrating the wall surface of the engagement recess and supplying cooling fluid toward the engagement recess;
One end is formed through the co-rotation prevention protrusion, or is formed so as to pass through the co-rotation prevention protrusion and the casing, and in an engaged state in which the co-rotation prevention protrusion engages with the engagement recess. a second supply flow path portion whose side opening communicates with the downstream opening of the first supply flow path portion;
The casing is provided outside the casing, and an opening at one end communicates with the downstream opening of the second supply flow path, and an opening at the other end is located near the surface of the grindstone, and is directed toward the surface of the grindstone. A cooling fluid supply structure characterized by comprising: a third supply flow path section for supplying cooling fluid. The engagement recess is formed in a mounting member separate from the main shaft housing that is attached to the front end surface of the main shaft housing,
2. The cooling fluid supply according to claim 1, wherein the first supply flow path section includes a main shaft internal flow path formed in the main shaft housing and a main shaft external flow path formed through the mounting member. structure. 3. The cooling fluid supply structure according to claim 2, wherein the mounting member is removably fixed to the tip surface of the spindle housing via a screw that engages with a screw hole formed in the tip surface of the main shaft housing. . 4. The cooling fluid supply structure according to claim 1, wherein the first supply flow path is a linear flow path extending in the axial direction of the main shaft. The cooling fluid supply according to any one of claims 1 to 4, wherein the second supply flow path section is a linear flow path extending in the axial direction of the main shaft in the engaged state. structure. 1 . The first supply flow path portion and the second supply flow path portion, in the engaged state, extend linearly in the axial direction of the main shaft and are disposed coaxially with each other. 6. The cooling fluid supply structure according to any one of 5 to 5. 7. The cooling fluid supply structure according to claim 1, wherein the third supply flow path section is formed by flexible piping.

Images